from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.views import generic
from django.utils import timezone
from rest_framework import viewsets

from .models import Choice, Question
from .serializers import QuestionSerializer, ChoiceSerializer
from mysite.core.utils import Utils
from users.models import UserProfile


class IndexView(generic.ListView):
    template_name = 'polls/index.html'
    context_object_name = 'latest_question_list'

    def get_queryset(self):
        """Return the last five published questions."""
        return Question.objects.filter(
            pub_date__lte=timezone.now()
        ).order_by('-pub_date')[:5]


class DetailView(generic.DetailView):
    model = Question
    template_name = 'polls/detail.html'

    def get_queryset(self):
        """
        Excludes any questions that aren't published yet.
        """
        return Question.objects.filter(pub_date__lte=timezone.now())


class ResultsView(generic.DetailView):
    model = Question
    template_name = 'polls/results.html'


def vote(request, question_id):
    question = get_object_or_404(Question, pk=question_id)
    try:
        selected_choice = question.choice_set.get(pk=request.POST['choice'])
    except (KeyError, Choice.DoesNotExist):
        # Redisplay the question voting form.
        return render(request, 'polls/detail.html', {
            'question': question,
            'error_message': "You didn't select a choice.",
        })
    else:
        selected_choice.votes += 1
        selected_choice.save()
        # Always return an HttpResponseRedirect after successfully dealing
        # with POST data. This prevents data from being posted twice if a
        # user hits the Back button.
        return HttpResponseRedirect(
            reverse('polls:results', args=(question.id,)))


class QuestionViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows users to be viewed or edited.
    """
    queryset = Question.objects.all()
    serializer_class = QuestionSerializer

    def get_queryset(self):
        queryset = Question.objects.all()
        question_text = self.request.query_params.get("question_text", None)
        if question_text is not None:
            queryset = queryset.filter(question_text=question_text)

        pub_date = self.request.query_params.get("pub_date", None)
        if pub_date is not None:
            start, end = pub_date.split("to")
            if start and start.strip() != '':
                queryset = queryset.filter(
                    pub_date__gte=Utils.parse_datetime(start))

            if end and end.strip() != '':
                queryset = queryset.filter(
                    pub_date__lte=Utils.parse_datetime(end))

        return queryset

    def perform_create(self, serializer):
        serializer.save(
            owner=self.request.user,
            tenant=UserProfile.objects.get(user=self.request.user).tenant)


class ChoiceViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows users to be viewed or edited.
    """
    queryset = Choice.objects.all()
    serializer_class = ChoiceSerializer
